Motor driven tool switch



Oct. 10, 1933. F. w w Pp 'r MOTOR DRIVEN TOOL SWITCH Original Filed April 16, 1950 2 Sheets-Sheet 1 I I l I l IL Oct. 10, 1933. -w WA PAT 1,929,662

MOTOR DRIVEN TOOL SWITCH Original Filed April 16, 1930 2 Sheets-Sheet 2 Patented oron DRIVEN 'rooL swrrcn '1 J 1 Fred WfWappat, Pittsburgh, Pa; assignonto Wappat, Incorporated, a corporation of Penn- 'sylvania fol-inner application August 16, 1930, Serial No r 475,687, now .Patent' No. 1,830,579....Divided a and this applicationApril 23,1931. Serial No.

The invention relates to motor driven tool switches and constitutes a division of my application, Serial No. 475,687, filed August 16, 1930, "n'owPatentNumber 1,830,580. The invention is :3 i particularly useful, connection with electric handsaws, such as that shown in r'nyPatent No. 1,623,290, butis not confined to use with electric has-'for'its principal objects; (1) the provision of 1 improved safety means in connection with the hand lever carried in the handle of the tool for operating'the electric switch whereby accidental starting of the motor is avoided; and, (2) the 1 provision of means whereby said lever may be locked in operative position under certain conditions of use in order to relieve the operator of the necessity of holding the lever in such position. 'One' embodiment of the inventionis illustrated in Figure 1 is a perspective view of a motor drivig'o'. the accompanying drawings, wherein:-

en' saw with the switch construction applied thereto. Fig. 2 is a front view of the machine.

Fig. 3 is a detail sectional view through the i handle ofthe tool Showing the safety device in locking position preventing the "accidental operation of the to that'of Fig. 3, but showing the parts in operating position. AndFig. 5 is another section 1 showing the parts locked in operating position.

Referring provided at an electric motor suitably mounted in the frame and provided with a shaft 4 carrying the worm 5 1, and 5, wherein 13 is a snap switch having a.

and carryin saw 8; 9 is switch lever. Fig. 4 is a view similar to the drawings, 1 is the saw frame one end with a handle 2; 3 (Fig. 2) is i 5; 6 is a shaft extending transversely of the frame g'the worm wheel 7 and the circular a guard or shield integral with the frame and surrounding the upper half of the saw;

10 is a movable guard casing or shield, similar to ithat of my guard being patent heretofore referred to, said pivoted on the frame concentric with the axis of rotation of the saw or approximately so and being adapted to telescope into the fixed casing when swung to the rear and 11 is the base iplate of'the machine on which the frame 1 is mounted fo r tilting and depth adjustments as is well known in the art.

The device for operating the, switch which starts and stops the motor is shown in Figs. 3, 4,

trigger 14 operated by the slide'rodl5, and 16 an operative member, preferably a lever,.pi,v-

oted at 17 in the handle 2.- The switch is so confull line pos structed that the trigger is yieldingly held in the ition of Fig. 3, at which time the cirg '5 Claims. (cram- 1) v Fig. 4. In order toprevent the motor frombeing Ihandsaw'a'being' designed for use'with electrically operated hand toolsof all kinds. The invention I started accidentally when the operator grasps the handle to move the machine,-the detent 18 pivoted at 19 and normally pressed to the position shown in Fig. 3 by the spring 20 is provided. The end of this detent engages a shoulder 21 on the lever, thus preventing it from being accidentally swung to the right around its pivot 1'7. The detent has a thumb piece 22 projecting through an opening in the handle. In order to release the lever from the detent when it is desired to start the motor; the operator first presses the end 22 inward, thus disengaging the inner end of the detent from the shoulder 21. The lever may 15 then be swung to its fon position, as shown in Fig. 4. I

In some cases, it may be desirable tolock the lever 16 in on" position, as for instance, when the saw is turned upside down and clamped in such position in order touse its base plate 11 as a saw table over which the members to be cut are moved, and in order to so lock the lever it is provided with a shoulder 23 adapted to be engaged and held by the recess 24 in the detent 5 when the parts are moved to the position of Fig. 5. This engagement is secured by pushing the thumb piece 22 down fromthe position of Fig. 4

to that of Fig.5 and allowing the lever to swing. slightly to the left from the position of Fig. 4 to the position of Fig.5 so that the shoulder engages the recess. To release the parts and allow them sitioned on thehandle sothat the grip of the operator on the handle in supporting the tool will 05.

- move the switch to complete the circuit through the motor, and a releasable detent on the handle locking the member against said movement.

2. Meansfor controlling the operation of an electric hand tool having a frame, a tool mounted 1 for operation therein, an electric motor on the frame for driving the tool, a handle on the frame, and a switch for controlling the flow of current from a source of supply to said motor, comprising a movable member for operating the switch positioned on the handle so that the grip of the operator on the handle in supporting the load will move the switch to complete the circuit through the motor, and a releasable detent on the handle locking the member against said movement, said detent being positioned so that it may be engaged by the thumb of the operator to move it to release position while his fingers grip said handle and said member.

3. Means for controlling thewoperation of an electric hand tool having a frame, a tool mounted for operation therein, an electric motor on the frame for driving the tool, a handle on the frame, and a switch for controlling the flow of current from a source of supply to said motor, comprising a movable member for operating the switch positioned on the handle so that the grip of the operator on the handle in supporting the load will move the switch to complete the circuit through the motor, a releasable detent on the handle for locking the member "against said movement, and

releasable means for locking the member in the positionto which it is moved to complete said circuit. 7

4. Means for controlling the operation of an the handle for locking the member against said movement, and means on the detent for also locking the member in the position to which it is moved to complete said circuit.

5. Means for controlling the operation of an electric handtool having a frame, a tool mounted for operation therein, a motor on the frame for driving the tool," a handle on the frame, and a switch controlling the flow of current from a source of supply to said motor, comprising a movable member for operating the switch positioned on the handle so that the grip of the operator on the handle will move the switch to complete the circuit through the motor, a releasable detent on the handle for locking the member against said movement, and means on the detent for also locking the member in the position to which it is moved to complete said circuit, said last means being arranged to release the member when such member is given a. further movement.

- FRED W. WAPPAT. 

